Sinclair ZX Spectrum Introduction Manual page 22

Chapter 5
If the program is now RUN two columns should appear the first with values of x, the
second with values of x*x or x squared. It is possible to label these columns by
adding another line, like this
5 PRINT "x","x*x"
Notice that although this has been entered after all the other lines because it has a
lower line number the computer automatically puts it in the correct place.
Try writing programs using other mathematical functions. If you have any doubt
about how to use them refer to the appropriate pages in the BASIC programming
manual.
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